China on Wednesday called on Syria to heed a plan aimed at bringing peace to the conflict-ridden country, saying it was "deeply concerned" by the continuing violence.

The call came after the Syrian government missed a key Tuesday deadline to withdraw troops from populated centers, under the six-point plan brokered by U.N.-Arab League envoy Kofi Annan.

Israeli Prime Minister Benjamin Netanyahu will meet his Palestinian counterpart Salam Fayyad in Jerusalem next week, a spokesman from the Israeli leader's office told Agence France Presse.

A Palestinian official had on Tuesday said the two men would meet on April 17, and on Wednesday, Netanyahu's spokesman Ofir Gendelman confirmed the date.

U.N.-Arab League envoy Kofi Annan warned on Wednesday it would be "disastrous" if rebels fighting the Syrian regime were to be armed, as proposed by Saudi Arabia and Qatar.

"I've always said the militarization of the conflict will be disastrous," Annan told a news conference in Tehran during a visit to Iran, Syria's chief ally in the Middle East.

Syrian forces shelled the flashpoint city of Homs on Wednesday and raided other parts of the country, killing eight civilians as they pressed their assaults on protest hubs, monitors said.

The attacks occurred a day after a U.N.-Arab League peace plan was scheduled to enter into effect, but envoy Kofi Annan said Wednesday there was still a chance to salvage his bid to end hostilities within another 24 hours.

Shots fired by Syrian forces early Wednesday hit a Syrian refugee camp just across the border with Turkey, Turkish media reported.

News channel CNN-Turk showed images of automatic rifle fire towards Turkish territory from a border surveillance building flying the Syrian flag near Kilis in southeastern Turkey.

U.S. Secretary of State Hillary Clinton said Tuesday she would tell Russia that the risk of civil war was rising in Syria, adding that she expected "rough" diplomacy ahead.

Clinton said she would raise the Syria crisis when she meets Foreign Minister Sergei Lavrov in talks among foreign ministers of the Group of Eight major economies starting in Washington on Wednesday.

The U.N. Security Council on Tuesday called on President Bashar al-Assad to keep a Thursday deadline for a complete ceasefire in the Syria conflict.

In a statement read by U.S. ambassador Susan Rice, the council backed a demand by U.N.-Arab League envoy Kofi Annan for the Syrian government to make a "fundamental change of course" to end hostilities by 6:00 am Damascus time on Thursday.

An explosive device was thrown at a convoy carrying the head of the United Nations mission to Libya on Tuesday, a U.N. spokeswoman said, adding that there were no casualties.

"While on a visit to Benghazi, the head of the United Nations Support Mission to Libya had what appeared to be an explosive device thrown at his convoy," Hua Jiang said.

The Palestinians have sent a letter to the United Nations Security Council seeking condemnation of Israeli settlement activity, the Palestinian foreign minister said on Tuesday.

Riyad al-Malki said the Palestinian envoy to the U.N., Riyad Mansour, had submitted letters to the council and U.N. Secretary Ban Ki-Moon on Monday, ahead of a meeting of the peacemaking Quartet in Washington on Wednesday.

Ninety people including 66 civilians were killed across Syria on Tuesday, the day the government was expected to pull its forces from protest hubs under a U.N.-Arab League peace plan, monitors said.

The Local Coordination Committees, the main activist group spurring protests on the ground, said security forces killed 30 people in Homs, nine in Idlib, 22 in Hama, five in Daraa, two in Aleppo, one in the Damascus suburb of Harasta and one in Deir al-Zour.